In recent years, with the increase in speed of data communication, optical communication using optical cables is replacing communication using metallic cables and becoming the main stream. As an optical waveguide device which performs optical communication, for example, as shown in FIG. 8A, there is an optical waveguide device 200 optically connected to an optical cable 220 and the optical waveguide device 200 splits the light guided by the optical cable 220.
The optical cable 220 includes multiple or single optical fiber line 222 inside, and transmits light, which is guided by the optical fiber line 222, in an extending direction. The optical waveguide device 200 includes on a substrate 210 an optical waveguide section 211 and a connection section 212 for connecting the optical waveguide section 211 and the optical fiber line 222. The optical waveguide section 211 includes a core 2111 which is formed with a plurality of branches in a Y-shape and covered with cladding 2112, and the core 2111 splits and outputs the input light (or on the contrary, the core 2111 may assemble and output the input light).
As shown in FIGS. 8A and 8B, the connection section 212 is formed with V-grooves 215 which allows optical fiber lines 222 to fit on the substrate 210, and connects the optical guided wave between the optical fiber lines 222 and the core 2111 by fitting the optical fiber lines 222 exposed at the end of the optical cable 220 along walls of the V-grooves 215 for alignment (passive alignment) as well as pressing the optical fiber lines 222 with a glass block 213 and bonding and fixing the optical fiber lines 222 with an adhesive member 214 nipped with a pressing face of the glass block 213 and the walls of the V-grooves 215.
The patent document 1 shows a structure similar to the above-described structure where an optical fiber is inserted in a V-groove to perform alignment of an optical fiber end face and an optical waveguide such as an optical splitter and the optical fiber is pressed with a glass block from above to be bonded and fixed. Also, a technique to reduce core material which results when an optical waveguide is formed by a duplication method (or a stamper method) and interferes when an optical cable is bonded and fixed to a groove is disclosed.
As described above, as for a connection in optical communication between an optical cable and an optical device such as an optical splitter, Laser Diode (LD), Vertical-Cavity Surface-Emitting Laser (VCSEL), Photo Diode (PD), etc. or a connection between optical cables, it is important to perform accurate alignment in order to reduce loss in the connecting area and it is important to fix the connection so that the connection does not become misaligned even when a certain amount of external force is applied.
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2004-20656